Is it possible to become famous without successful parents?

Answer 1

A similar all-pass filter can be implemented by interchanging the position of the resistor and capacitor, which turns the high-pass filter into a low-pass filter. The result is a phase shifter with the same quadrature frequency but a 180 degree shift at high frequencies and no shift at low frequencies. In other words, the transfer function is negated, and so it has the same pole at -1/RC and reflected zero at 1/RC. Again, the phase shift of the all-pass filter is double the phase shift of the first-order filter at its non-inverting input.